Generally in a color photographic light-sensitive material, when the said light-sensitive material is exposed to light imagewise and then subjected to color-development, an oxidized p-phenylenediamine derivative reacts with a coupler to form an image. In this system, color reproduction by the subtractive color technique is used, and, to reproduce blue, green, and red colors, dye images of yellow, magenta, and cyan in color, respectively complementary to blue, green, and red, are formed.
Color development is accomplished by immersing (dipping) an exposed color photographic light-sensitive material in an alkaline aqueous solution containing a p-phenylenediamine derivative (a color-developing solution).
Generally, when such a processing is performed, it is necessary to use a tank for dipping a color photographic light-sensitive material in a color-developing solution, and a replenisher tank for stocking a replenisher to replenish an exhausted color-developing solution, which results in large-size processing equipment.
For a minilab and the like, in which dispersion processing is carried out in particular, the equipment is preferred to be of small size. Consequently, it is required to reduce the above-mentioned tanks for the equipment of small size.
To reduce the tanks, a first consideration is to eliminate the processing tank. A method for achieving this is to coat a processing solution on the surface of a light-sensitive material, instead of stocking a tank with the processing solution, as described in, for example, Japanese registered patent No. 2612205. However, in this method, when a p-phenylenediamine derivative necessary for forming color is incorporated in a processing solution, a large amount of the processing solution must be coated, or alternatively the concentration of the p-phenylenediamine derivative in a processing solution must be increased. In the former case, a large amount of the processing solution is used, so that a stock tank must be large-sized. According to this method, drawbacks arise in that a large amount of a processing waste solution is discharged. On the other hand, in the latter case, because the solubility of the p-phenylenediamine derivative in water is limited, a high concentration of the p-phenylenediamine derivative causes such a problem as its precipitation.
In the meantime, oxidation of the p-phenylenediamine derivative is performed by a silver halide incorporated in a light-sensitive material. The silver in the light-sensitive material, after development, remains therein as a metallic silver. The metallic silver is preferably removed from the light-sensitive material, because it turns black and therefore deteriorates a purity of the color image. Conventionally, the metallic silver was bleached into silver ions, so that they were removed with an undeveloped silver halide from a light-sensitive material by fixing. Because a large amount of an inorganic salt, such as an iron salt, a chelating agent, and the like, is contained in a bleach-fix solution having such a bleach-fixing capacity, a serious problem has been caused by the waste solution processing of bleach-fix solutions. Further, in a minilab or the like, in which dispersion processing is conducted, a device is preferably of small size. In order to conduct bleaching and fixing, a processing tank and a tank for stocking a bleach-fix solution, or the like, are needed. These are one obstacle to miniaturization of the device. A method to remove such a bleach-fixing step from a processing is to conduct intensification processing with hydrogen peroxide, as described in, for example, the Journal of the Society of Photographic Science and Technology of Japan, Vol. 51, No. 3, p. 191 (1988), JP-B-61-48148 ("JP-B" means examined Japanese patent publication), JP-B-63-20330, JP-B-63-20332, and JP-A-3-111844 ("JP-A" means unexamined published Japanese patent application). Because an image amplified on a developed silver is formed by the intensification processing, a sufficient image density can be obtained, even though a light-sensitive material having a sharply reduced amount of silver is used. Therefore, color stain due to a metallic silver can be made a negligibly small, so that bleaching and fixing are not needed.
When such an intensification processing is carried out, a color-developing solution contains as an essential element: a p-phenylenediamine derivative, which is oxidized by a silver halide, to produce its oxidation product, which couples with a coupler, to form a dye; a peroxide, such as hydrogen peroxide, that intensifies silver; and an alkali, that dissociates the coupler and the p-phenylenediamine derivative, to accelerate the reaction. However, when a p-phenylenediamine derivative and a peroxide, such as hydrogen peroxide, coexist, they react with each other, in an oxidation-reduction reaction, such that a problem arises in that a processing solution becomes deteriorated. Further, the alkaline state causes a problem in that the peroxide, such as hydrogen peroxide, tends to be decomposed by itself.
To stabilize such a color-developing solution for intensification, it is conceivable that the p-phenylenediamine derivative should be removed from the color-developing solution.
When a p-phenylenediamine derivative is removed from the color-developing solution, no coloring occurs.
One method conceivable for solving the above problems is to incorporate a p-phenylenediamine derivative, or another compound having the same function, in a light-sensitive material. If the p-phenylenediamine derivative, or the another compound having the same function, is incorporated in a light-sensitive material, there is no need to incorporate a p-phenylenediamine derivative in the processing solution. An example of a method proposed in which a p-phenylenediamine derivative, or another compound having the same function, is incorporated in a light-sensitive material, is to built-in an aromatic primary amine, or its precursor, in a light-sensitive material. Examples of the aromatic primary amine developing agent or its precursor, each of which can be built-in the light-sensitive material, include those as described in, for example, U.S. Pat. Nos. 2,507,114, 3,764,328, and 4,060,418, JP-A-56-6235, JP-A-58-192031, and Japanese Patent Application Nos. 266793/1997, 265568/1997, and 265569/1997. Of these compounds, a compound that releases an aromatic primary amine upon a rearrangement reaction due to a peroxide, as described in Japanese Patent Application Nos. 266793/1997, 265568/1997, and 265569/1997, is excellent in the compatibility of storage stability and coloring property. Another example of an effective means proposed is a method in which a stable, color-forming reducing agent is built in a hydrophilic colloid layer, with examples including hydrazine compounds as described in, for example, European Patent Nos. 0545491A1 and 0565165A1, JP-A-8-286340, JP-A-8-292529, JP-A-8-297354, JP-A-8-320542, and JP-A-8-292531; and sulfonamidophenol compounds as described in, for example, U.S. Pat. No. 4,021,240 and Research Disclosure No. 15108 (November 1976). These color-forming reducing agents have characteristics of excellent storage stability and high coloring property.
An alkaline solution becomes necessary to color a compound incorporated in a light-sensitive material, such as an aromatic primary amine or its precursor, or a color-forming reducing agent, as mentioned above. As a method for providing a small amount of the alkaline solution on the surface of a light-sensitive material, first, a method in which a light-sensitive material is passed through a slit, as described in Japanese registered patent No. 2612205, is conceivable. However, in such a method, a large amount of an alkaline solution must be used. In contrast, if a method in which an alkaline solution is coated in the form of a thin layer on the surface of a light-sensitive material by a roller coater, a felt-type coater (a felt cloth), a sponge coater, or the like, as described in a specification of the above-mentioned Japanese registered patent, is used, the amount of the alkaline solution to be used can be reduced sharply. However, in these methods, the coating portion of the coating apparatus is gradually stained with a material that flows out of a light-sensitive material, which can result in a change of processing. Therefore, preferably the coating portion of the coating apparatus is kept out of contact with a light-sensitive material. Further, occurrence of unevenness in coating causes non-uniformity in coloring. Consequently, it is necessary to uniformly coat a processing solution at the time of a coating processing. As a method for uniformly coating a processing solution on the surface of a light-sensitive material without contact with a coating apparatus, there is a method in which a processing solution is atomized from a narrow nozzle and blown onto a light-sensitive material, as described in JP-A-9-179272 and JP-A-6-324455.
As a method for uniformly coating a processing solution without contact with a light-sensitive material, a method for coating a processing solution using a processing solution-coating apparatus as described in JP-A-9-179272, is especially effective.
Further, as another measure to make small a processing apparatus, a consideration is to remove the bleach-fixing step from the processing steps that are usually performed in a so-called conventional image formation, including a color-developing step, a bleach-fixing step, and a washing step, to thereby make small the processing apparatus.
As mentioned above, a drastic miniaturization of the processing apparatus can be achieved by coating an alkaline solution containing a peroxide, such as hydrogen peroxide, on a light-sensitive material containing an aromatic primary amine or its precursor, or a color-forming reducing agent, by means of a processing solution-coating apparatus, as described in JP-A-9-179272. However, an alkaline condition is necessary for oxidation of an aromatic primary amine or its precursor, or a color-forming reducing agent, and moreover nozzle holes of the processing solution-coating apparatus as described in JP-A-9-179272, from which a processing solution is sprayed, are preferably made of a metal, from a viewpoint of easy production. However, such a metallic part functions as a catalyst of the decomposition of hydrogen peroxide or the like under such a high pH condition, to thereby release oxygen. The thus-generated oxygen gas forms bubbles, which block the above-described nozzle holes, and a processing solution cannot be sprayed from such blocked nozzle holes. Consequently, a problem arises in that undeveloped portions, i.e. so-called "white spots", are generated in the processed light-sensitive material.
In the meantime, even though a p-phenylenediamine derivative has been removed from a color-developing solution for intensification, an alkali and a peroxide, such as hydrogen peroxide, still coexists in the color-developing solution for intensification, so that it is difficult to maintain the stability of the peroxide, such as hydrogen peroxide. In order to solve this problem, it is conceivable that the alkali and hydrogen peroxide may be separately applied to a light-sensitive material. When an alkali solution and a peroxide-containing solution are supplied according to an ordinary tank processing, a problem still arises in that the alkali solution that is initially supplied is gradually taken into the peroxide-containing solution, whereby stability of the peroxide-containing solution is deteriorated. Accordingly, the peroxide-containing solution at the latter part, when contacted with a light-sensitive material, cannot be used for a long time. Therefore, it is necessary to use up the peroxide-containing solution. However, a drawback arises in that a large amount of a waste solution is discharged by the tank processing.
In order to reduce such an amount of the waste solution, a slit development is proposed, as described in, for example, JP-A-63-235940, JP-A-64-26855, JP-A-2-118633, and JP-A-2-137843. If this method is used, a single use of the processing solution is possible, even in a small amount of the solution. However, a slit having the width of several tens of .mu.m must be used in order to attain the same effect as in replenishment processing, in which a tank is used. Therefore, it is very difficult to pass the light-sensitive material through such a slit.
Different from the above-mentioned methods is one conceivable in which a processing solution is coated in a small amount and uniformly on the surface of a light-sensitive material. A known coating method is to coat a processing solution by a roller coater, a felt coater (a felt cloth), a sponge coater, or the like, as described in, for example, Japanese Registered Patent No. 2612205, and a coating method by spraying a processing solution from a narrow nozzle, as described in JP-A-6-324455 and JP-A-9-17927. Even when a processing solution is coated onto the surface of a light-sensitive material, when a coating part of the coating device is in contact with the light-sensitive material, the coating part becomes gradually contaminated with alkali, so that a peroxide decomposes by itself at the coating part. Consequently, a problem arises in that a processing solution is coated unevenly due to bubbles generated therein. Accordingly, in order to coat a peroxide-containing solution onto the surface of a light-sensitive material, it is necessary to use a method for coating the same on the light-sensitive material without contact with a coating device. Particularly effective is a method for coating a processing solution by means of a processing solution-coating device, as described in JP-A-9-179272.
As a method for coating a water on a material without contact, the use of coating device, described in JP-A-9-179272, is known. The coating device described in this specification is used to supply a water for generating an alkali from an alkali-generating agent, when heat development is performed. One of the characteristics of the coating method described in this specification is to spray a liquid, like a water, from a nozzle of very small size, so as to coat the same. There is no problem with a liquid that contains substantially no solute, like a water. However, such a problem as "blockage of the nozzle" arises in a solution in which a lot of solutes are dissolved, when a solvent is evaporated from the solution. Further, if an amount of an organic compound dissolved in a processing solution becomes large, inclination occurs in spray from a nozzle, which results in non-uniformity of coating. Accordingly, when a processing solution is coated by such a coating method, it is necessary to reduce the solute content in the processing solution as much as possible.
In such a situation, it has been desired to materialize a method for forming an image in which both a color developer for intensification and a light-sensitive material are stable and are not deteriorated with the passage of time, and further an even and uniform image can be formed by a processing method in which a simple intensification development that does not need a bleaching is used.